Peak flood discharge data from records of South African rivers at 83 places have been analysed and it has been found that the country can be conveniently sub-divided into seven regions of reasonably similar mean flood characteristics.

The paper recorded observations made of the movement of a ring-tension biological filter wall. Examination of the interaction between wall tension and the development of active and passive pressures within the stone mass revealed that outward displacement of the wall occurred on each temperature cycle.